Details

Request filtering replaces URLScan in IIS, enabling administrators to create a more granular rule set with which to allow or reject inbound web content. By setting limits on web requests, it helps to ensure availability of web services and may also help mitigate the risk of buffer overflow type attacks. The MaxURL Request Filter limits the number of bytes the server will accept in a URL.

Solution

Follow the procedures below for each site hosted on the IIS 10.0 web server:

Click the site name under review.

Double-click the ‘Request Filtering’ icon.

Click ‘Edit Feature Settings’ in the ‘Actions’ pane.

Set the ‘maxURL’ value to ‘4096’ or less.

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_IIS_10-0_Y20M10_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Windows.

References

• 800-53|SC-5(1)
• CAT|II
• CCI|CCI-001094
• Rule-ID|SV-218753r558649_rule
• STIG-ID|IIST-SI-000225
• STIG-Legacy|SV-109331
• STIG-Legacy|V-100227
• Vuln-ID|V-218753

Source

• Tenable.com/audits